Initial interactions with prey may affect a predator's subsequent foraging
success. With experience, second-instar Misumena vatia spiderlings (Thomisi
dae) that had recently emerged from their egg sacs oriented faster to fruit
flies (Drosophila melanogaster) than naive individuals. Orientation time o
f these spiderlings decreased rapidly for the first two to three runs (ever
y third day) in a simple laboratory setting, and then remained low and rela
tively constant. Time to capture a fly also declined initially, but subsequ
ently became extremely variable, increasing prior to moult. Increase in cap
ture time and the failure to capture prey appeared associated with impendin
g moult, rather than satiation. Spiderlings oriented to prey more rapidly a
t the beginning of the third instar than at the start of the second instar,
suggesting that experience still enhanced performance after a moult cycle.
Overall capture times at the beginning of the third instar, decreased from
those at the end of the second instar, but did not differ significantly fr
om the beginning of the second instar, although spiderlings gaining the mos
t biomass had the shortest mean capture times. In a second experiment, time
to orient and time to capture prey did not differ in naive, second-instar
siblings run 1 and 3 days after emergence from their egg sacs. However, 3-d
ay individuals that had captured prey each day (confiscated before they cou
ld feed) oriented faster than naive 3-day-old siblings, but did not differ
in the time taken to capture prey. Experience, rather than age or energetic
condition, best explains these changes in performance. (C) 2000 The Associ
ation for the Study of Animal Behaviour.